Note: Descriptions are shown in the official language in which they were submitted.
CA 02757022 2011-11-01
LIGHT ENGINES FOR LUMINAIRES
FIELD
[0001] Embodiments of the present invention relate to light engines for
luminaires.
BACKGROUND
[0002] Most luminaires that use light emitting diodes ("LEDs") are powered by
light boards of rectangular shape with the LEDs laid out on the light boards
in a
rectangular grid or a line of LEDs. Light boards of this shape are not
conducive to
inclusion in, or configurable for inclusion in, a wide variety of luminaire
shapes.
[0003] The optics for use with such light boards usually include Type I, Type
II,
Type III, Type IV, or Type V lenses. These lens types are well known in the
industry
and represent the distribution pattern that light will have when exiting the
lenses. The
lenses used with light boards in typical LED luminaires are typically all of
the same
distribution (i.e., are all Type I or of Type II, etc.) such that all of the
light exiting the
luminaire is aimed in a specified and predetermined direction.
SUMMARY
[0004] Certain embodiments of the present invention provide light engines for
luminaires. Embodiments of the light engines include a printed circuit board
("PCB")
of a geometric shape, light emitting diodes ("LEDs") provided on the PCB, and
an optic
that is mounted on the PCB to cover the LEDs.
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[0005] Other embodiments are directed to luminaires in which one or a
plurality of
such light engines are mounted. The light engines may be arranged in any
orientation
within a luminaire and such arrangement may be specifically tailored to the
geometric
shape of the luminaire, if desired. The light engine design of embodiments
contemplated herein allows customization of the pattern of emitted light from
a
luminaire, which is impacted by (1) the type of optic (i.e., Type I-V)
incorporated into
each light engine in the luminaire and (2) the rotational orientation of each
optic in the
light engines. In some embodiments, the direction that light emitted from the
LEDs is
aimed by the optic may be altered by rotationally altering the position of the
optic
relative to its associated PCB.
[0006] The terms "invention," "the invention," "this invention" and "the
present
invention" used in this patent are intended to refer broadly to all of the
subject matter of
this patent and the patent claims below. Statements containing these terms
should not
be understood to limit the subject matter described herein or to limit the
meaning or
scope of the patent claims below. Embodiments of the invention covered by this
patent
are defined by the claims below, not this summary. This summary is a high-
level
overview of various aspects of the invention and introduces some of the
concepts that
are further described in the Detailed Description section below. This summary
is not
intended to identify key or essential features of the claimed subject matter,
nor is it
intended to be used in isolation to determine the scope of the claimed subject
matter.
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The subject matter should be understood by reference to the entire
specification of this
patent, all drawings and each claim.
BRIEF DESCRIPTION OF THE FIGURES
[0007] Illustrative embodiments of the present invention are described in
detail
below with reference to the following drawing figures:
[0008] FIG. 1 is an exploded view of one embodiment of a light engine.
[0009] FIG. 2 is a perspective view of the light engine of FIG. 1 assembled.
[0010] FIG. 3 is an exploded view of another embodiment of a light engine.
[0011] FIG. 4 is a perspective view of the gasket shown in FIG. 3 mounted on
the
PCB shown in FIG. 3.
[0012] FIG. 5 is an enlarged section view taken at inset 5 in FIG. 4.
[0013] FIG. 6 is a perspective view of the light engine of FIG. 3 assembled.
[0014] FIG. 7 is a partial perspective view of a luminaire in which light
engines
according to some embodiments are positioned.
[0015] FIGS. 8A-8X are schematic illustrations of light engines in various
configurations according to some embodiments of the invention.
[0016] FIGS. 9A-D illustrate light engines according to embodiments of the
invention
positioned within luminaires of different shapes.
[0017] FIG. 10 is an exploded view of an embodiment of a wall sconce
illuminated
by an embodiment of a light engine.
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[0018] FIG. 11 schematically illustrates embodiments of light engines
connected to
power sources.
DETAILED DESCRIPTION
[0019] The subject matter of embodiments of the present invention is described
here
with specificity to meet statutory requirements, but this description is not
necessarily
intended to limit the scope of the claims. The claimed subject matter may be
embodied
in other ways, may include different elements or steps, and may be used in
conjunction
with other existing or future technologies. This description should not be
interpreted as
implying any particular order or arrangement among or between various steps or
elements except when the order of individual steps or arrangement of elements
is
explicitly described.
[0020] Certain embodiments of the present invention provide light engines 10
for
luminaires. Embodiments of the light engines include a printed circuit board
("PCB")
12, light emitting diodes ("LEDs") 14 provided on the PCB 12, and an optic 16
that is
mounted on the PCB 12 to cover the LEDs 14. A illustrative example of an
embodiment
of a light engine 10 is shown in FIG. 1. While the light engines disclosed
herein are
discussed for inclusion in luminaires, they may be used in any application.
[0021] The PCB 12 can be any geometric shape, including, but not limited to,
square,
rectangular, triangular, pentagonal, hexagonal, octagonal, circular, oval, or
any
equilateral or non-uniform geometric shape. Hexagonal and octagonal PCBs 12
are
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shown throughout this disclosure for purposes of illustration; however,
embodiments
are certainly not intended to be limited to such shapes. Wire leads 13 are
connected to
and extend from the PCB 12.
[0022] A plurality of LEDs 14 are mounted on the PCB 12. The LEDs may be
single-
die or multi-die LEDs, DC or AC, or can be organic light emitting diodes.
White, color,
or multicolor LEDs may be used. Moreover, the LEDs 14 mounted on a PCB 12 need
not all be the same color; rather, mixtures of LEDs 14 may be used.
[0023] Any number of LEDs 14 may be mounted on a PCB 12 in any configuration.
In some embodiments, the LEDs 14 are mounted on a PCB 12 in a polar array
about a
center point (as seen in FIG. 1) but such configuration need not be the case.
The shape
of the PCB 12 may help to dictate natural arrangements of the LEDs 14 on the
PCB 12.
[0024] An optic 16 is positioned over each PCB 12. In some embodiments, the
optic
16 can be, but does not have to be, the same shape and size of the PCB 12 on
which it is
mounted. The optic 16 includes a plurality of lenses 18 formed integrally in
the optic 16
(such as by molding). The optic 16 may be formed from a transparent material,
such as,
but not limited to, polymeric materials (e.g., polycarbonate or acrylic),
glass, topaz,
sapphire, epoxy resin, etc. In some embodiments, the lenses 18 of an optic 16
are
identical in that they are all of a single type (e.g., all Type I lenses, all
Type II lenses, all
Type III lenses, all Type IV lenses, all Type V lenses). In other embodiments,
a single
optic 16 may be provided with lenses 18 of different Types I-V. In some
embodiments,
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CA 02757022 2011-11-01
there is a 1:1 correspondence between the number of lenses 18 on the optic 16
and the
number of LEDs 14 on the PCB 12.
[0025] As shown in FIG. 2, the optic 16 is positioned over the PCB 12 so that
the
lenses 18 of the optic 16 align with the LEDs 14 mounted on the PCB 12. In
some
embodiments, the lenses 18 are centered directly on the LEDs 14. The optic 16
may be
retained on the PCB 12 using any mechanical retention method. In some
embodiments,
the retention method is non-permanent, thereby permitting the optic to be
removed
from the PCB or to move (such as via rotation) relative to the PCB, as
explained below.
In the illustrated embodiment of FIG. 2, the optic 16 fits over the sides of
the PCB 12.
[0026] FIG. 3 is an exploded view of an alternative embodiment of a light
engine 10'.
Flame barrier 22 is interposed between the PCB 12 and optic 16. The flame
barrier may
be manufactured from any material having suitable insulating properties,
including,
but not limited to, flame resistant polymeric materials, glass, or metal. In
some
embodiments, 3MTm's CeQUINTM insulating paper may be suitable. The flame
barrier
22 includes LED apertures 24 through which the LEDs 14 mounted on PCB 12 may
pass. The flame barrier 22 is optional and may not be needed in all
applications.
[0027] Light engine 10' further includes a gasket 28 that is adapted to
surround the
periphery of PCB 12 (see FIG. 4). The gasket 28 may include tabs 30 that fit
over the
corners of the PCB 12 to secure the gasket 28 to the PCB 12, as shown in FIG.
5. The
gasket 28 includes a slot for passage of the wire leads 13 coming off the PCB
12. A
thermally-conductive pad 32 may optionally be provided on the underside of the
PCB
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CA 02757022 2011-11-01
12 for thermal management purposes and more specifically for providing a path
for
dissipating heat generated by the LEDs 14.
[0028] In use, a plurality of light engines 10, 10' are mounted in a luminaire
31 (such
as that shown in FIG. 7). In some embodiments, the light engines 10, 10' are
mounted to
a metal casting 33 within the luminaire head 35. In the embodiment illustrated
in FIG.
3, the thermally-conductive pad 32 would be interposed between the underside
of the
PCB 12 and the casting 33.
[0029] Any retention method may be used to secure the light engines 10, 10' to
the
metal casting 33. By way only of example, screw(s) 26 may be provided to
secure the
PCB 12 (FIG. 2) or the flame barrier 22 (if provided), PCB 12, and thermally-
conductive
pad 32 (if provided) (FIG. 3) to the metal casting 33. Clips 34 with
associated mounting
screws 36 may then be used to secure the optic 16 over the mounted PCB 12
(FIG. 2) or
the mounted flame barrier 22 (if provided)/PCB 12/thermally-conductive pad 32
(if
provided) (FIG. 3). In some embodiments, the optic 16 is provided with
indentations 29
for receiving the arms of the clips 34. Any number of clips 34 may be used and
indentations 29 be provided. In use, the clips can be rotated (or loosened and
rotated)
so as to disengage the optic 16 and thereby permit rotation of the optic 16.
The clips 34
can then be re-secured over the optic 16 to hold the optic 16 in place in the
desired
rotational orientation. Any number of alternative mounting means and
configurations
may be used. For example, instead of clips 34, screws, brackets, or biasing
elements
(such as springs) may be used to retain the optic 16 over the PCB 12.
Moreover, it is
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possible that the flame barrier 22 not be secured at all with screws 26 but
rather just
interposed between the PCB 12 and the optic 16. Alternatively, the flame
barrier 22
could be mounted on pins extending from the optic 16 or from the PCB 12.
[0030] In some embodiments, the light engines used in a luminaire are all
identical
in that they have identically-shaped and sized PCBs 12, the same number and
arrangement of LEDs 14 on the PCBs 12, and/or the same type of optic 16
mounted on
each PCB 12. However, in other embodiments, the light engines provided in a
luminaire need not be identical. Rather, PCBs 12 of different shapes and sizes
may be
used in a single luminaire. Moreover, the number and arrangement of LEDs 14 on
such
PCBs 12 can differ, and optics 16 having lenses 18 with different
distributions may be
used in a single luminaire. By way only of example, one light engine in a
luminaire
may have an optic 16 with Type II lenses 18 while another light engine in the
luminaire
may have an optic 16 with Type III lenses 18.
[0031] The light engines may be arranged in any orientation within a luminaire
and
such arrangement may be specifically tailored to the geometric shape of the
luminaire,
if desired. FIGS. 8A-8X schematically represent octagonal light engines
(indicated
generally as 60) arranged in a variety of different configurations (e.g.,
clustered,
circular, semi-circular, oval, rectangular, square, diamond, linear, T-shaped,
X-shaped,
V-shaped, U-shaped, cross, serpentine, or triangular configuration). As stated
earlier,
however, the light engines may be of any geometric shape. The geometric shape
of the
PCBs 12 renders them suitable for use in a variety of luminaires having
different shapes
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CA 02757022 2011-11-01
and features. For example, the light engine 60 configuration of FIG. 8C would
be well-
suited in a luminaire having a rectangular head. The light engine 60
configuration of
FIG. 8D would be well-suited in a luminaire having a square head. The light
engine 60
configuration of FIG. 8Q would be well-suited in a luminaire having a circular
head
with a central opening in the head. FIGS. 8A-8X represent but a few of the
endless
possibilities of light engine configurations. Moreover, the light engine
configurations
need not match the shape of the luminaire. For example, the light engines
could be
installed in a circular pattern within a rectangular luminaire head.
[0032] FIGS. 9A-D illustrate hexagonal light engines (indicated
generally as 70)
arranged in different configurations. In FIG. 9A, the luminaire head 40 is
circular with a
central, circular aperture 42 (such as is shown in the luminaire of FIG. 7).
The light
engines 70 are arranged in clusters of three light engines 10 around the
aperture 42. In
FIG. 9B, the light engines 70 are arranged within a rectangular luminaire head
40. In
FIG. 9C, the light engines 70 are arranged within a hexagonal luminaire head
40. In
FIG. 9D, the light engines 70 are arranged within a trapezoidal luminaire head
40.
[0033] FIG. 10 illustrates an exploded view of another
embodiment of a luminaire,
and more particularly a wall sconce 80. The wall sconce 80 includes a metal
casting 82
with a light engine 84 (such as those disclosed above) mounted on the casting
82.
Multiple light engines 84 could be used. A face plate 86 is secured over the
metal
casting 82 (such as via coupling 87). In some embodiments, the face plate 86
includes a
design or logo 89. The face plate 86 can be any shape and is not limited to
the square 9
CA 02757022 2011-11-01
shape illustrated in FIG. 10. In use, the wall sconce 80 is mounted on a wall
so that the
face plate 86 is exposed on the wall. It may be desirable for some of the
light to be
distributed directly outwardly through the face plate 86 to illuminate any
design or
logo 89 on the face plate 86 and for other of the light to be distributed
radially
outwardly from the wall sconce 80 so as to illuminate the wall around the wall
sconce
80 (e.g., the periphery of the face plate 86). To accomplish this
distribution, the lenses
on the optic of the light engine 84 may have different distributions. By way
only of
example, the center LED of light engine 84 could have an associated lens
designed to
distribute the LED's emitted light directly outwardly from the PCB while each
of the
surrounding eight LEDs could have an associated lens designed to distribute
the LED's
emitted light radially outwardly from the PCB.
[00341 Using geometrically-shaped PCBs 12 ensures that the edges and/or
corners of
adjacent light engines can contact each other if desired. This can facilitate
electrically
connecting the light engines to a power source, as discussed below.
[0035] The light engines may be powered in a variety of different ways. In
some
embodiments, a single driver is provided, and each light engine is separately
connected
to the driver (e.g., such as by using connectors to connect leads from the
light engines to
a wiring harness from the driver). In another embodiment, a first light engine
is
connected to the driver and the other light engines are connected in series to
the first
light engine. By way only of example, the hexagonal light engines 70 shown in
FIGS.
9A-D could be connected at the corners where adjacent light engines 70 meet.
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[0036] In still another embodiment, multiple drivers are provided, each of
which is
connected to a first light engine 10a. The remaining light engines 10b-10d are
connected
in series to the first light engine 10a. This arrangement is shown
schematically in FIG.
11 where a first driver 46 and second driver 48 are connected to a first light
engine 10a.
Light engines 10b-10d are connected in series to first light engine 10a with
connectors
50. Bypass circuits may be used so that the a circuit can pass through a light
engine
without energizing the LEDs on that particular light engine but can energize
other light
engines in the series. By way only of example, using such bypass circuits a
driver can
energize every other light engine in the series. For example, in the example
shown in
FIG. 11, first driver 46 could energize light engines 10a and 10c and second
driver 48
could energize light engines 10b and 10d.
[0037] The light engine design of embodiments contemplated herein allows
customization of the pattern of light emitted from a luminaire. The light
distribution is
impacted by (1) the type of optic 16 (i.e., Type I-V) incorporated into each
light engine
in the luminaire and (2) the rotational orientation of each optic 16 in such
light engines.
[0038] In some embodiments, optics 16 having lenses 18 with identical optical
properties are used in all of the light engines in a luminaire. In other
embodiments,
light engines having lenses 18 with different distributions or optical
properties can be
provided in a single luminaire. The overall light distribution of the
luminaire is tailored
by coupling each PCB 12 with an optic 16 designed to distribute the light from
the LEDs
14 on the PCB 12 as desired.11
CA 02757022 2011-11-01
[0039] Because the optics 16 are releasably attached to, or otherwise movable
relative
to, the PCBs 12, the direction that the light emitted from the LEDs 14 on a
PCB 12 is
aimed by the optic 16 may be altered by rotationally altering the position of
the optic 16
relative to its associated PCB 12. The optics 16 may be rotated in any
suitable
increment, which will be dependent upon the shape of the PCB 12 and/or the
location
of the LEDs 14 on the PCB 12. For example, if the PCB 12 is square, in some
embodiments the optic 16 could be rotated in 90 increments. If the PCB 12 is
hexagonal
or octagonal, in some embodiments the optic 16 could be rotated in 60 and 45
increments, respectively. Thus, in some embodiments, the light emitted from
the LEDs
14 mounted on different PCBs 12 in the luminaire is aimed in specific
directions to
create a unique or customized light distribution simply by adjusting the
rotational
position of some of all of the optics 16 relative to their associated PCBs 12.
In this way,
a customer can customize the light distribution of the luminaire in the field
by aiming
the optics 16 as desired.
[0040] The foregoing is provided for purposes of illustrating, explaining, and
describing embodiments of the present invention. Further modifications and
adaptations to these embodiments will be apparent to those skilled in the art
and may
be made without departing from the scope or spirit of the invention. Different
arrangements of the components depicted in the drawings or described above, as
well
as components and steps not shown or described are possible. Similarly, some
features
and subcombinations are useful and may be employed without reference to other
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features and subcombinations. Embodiments of the invention have been described
for
illustrative and not restrictive purposes, and alternative embodiments will
become
apparent to readers of this patent. Accordingly, the present invention is not
limited to
the embodiments described above or depicted in the drawings, and various
embodiments and modifications can be made without departing from the scope of
the
claims below.
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